Burning Coolant at Idle
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Burning Coolant at Idle
Recently bought a new-to me 1996 Dodge Ram 1500 Sport 5.9 and have already searched and used the forum for a LOT of help - so thanks to everyone for that.
My first post comes because I am struggling with an issue here...
The truck has 178,000 miles on it and when I picked it up, it had two blown head gaskets, misfires, rough running, etc.. We tore everything down the day it came home and did a full-on gasket replacement, scraping, cleaning, etc. including plenum gasket - everything went pretty well and the truck has new life. The thing runs really well.
What I first thought was leftover coolant in the exhaust system is now showing itself as a lingering problem. The truck does not burn any coolant during normal driving (no signs of use at tank and no white smoke). If the truck is run up to temp by driving, then stops to idle for 2+ minutes, the exhaust note changes, the idle gets a bit rough, and a bit of white smoke (that smells like coolant) starts to come out the tailpipe. So, its getting coolant into the engine and burning it SOMEHOW.
The heads were checked for flatness as well as the block and it all looked good. I did a quick inspection of the heads and didn't see any obvious cracks. Intake manifold was gasketed and RTV'd per manual and properly torqued in sequence. Felpro gaskets were used which seemed pretty darn nice.
I am leaning towards the intake manifold gasket(s) being cocked/slipped/something but anyone have any other ideas?
My first post comes because I am struggling with an issue here...
The truck has 178,000 miles on it and when I picked it up, it had two blown head gaskets, misfires, rough running, etc.. We tore everything down the day it came home and did a full-on gasket replacement, scraping, cleaning, etc. including plenum gasket - everything went pretty well and the truck has new life. The thing runs really well.
What I first thought was leftover coolant in the exhaust system is now showing itself as a lingering problem. The truck does not burn any coolant during normal driving (no signs of use at tank and no white smoke). If the truck is run up to temp by driving, then stops to idle for 2+ minutes, the exhaust note changes, the idle gets a bit rough, and a bit of white smoke (that smells like coolant) starts to come out the tailpipe. So, its getting coolant into the engine and burning it SOMEHOW.
The heads were checked for flatness as well as the block and it all looked good. I did a quick inspection of the heads and didn't see any obvious cracks. Intake manifold was gasketed and RTV'd per manual and properly torqued in sequence. Felpro gaskets were used which seemed pretty darn nice.
I am leaning towards the intake manifold gasket(s) being cocked/slipped/something but anyone have any other ideas?
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Joined: Apr 2010
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From: Clayton MI
Intake gaskets would be more likely to dump coolant into the oil, than into the cylinders. Probably a bad head gasket, or, cracked head/block. Did you have them magnaflux the heads while they were in the shop?
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No, we did everything at my home garage so didn't magnaflux, etc. just a visual. Thanks for the ideas...
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Joined: Apr 2010
Posts: 87,397
Likes: 4,213
From: Clayton MI
If you have a cooling system pressure tester..... (these are not expensive, and can be rather handy to have around...)
remove radiator cap. Run the engine up to operating temp. Remove spark plugs. See if you get coolant running out of any of the cylinders....... you should roll the motor over by hand, with a socket on the crank bolt or some such, and see if anything comes out... or, you could crank the engine with the starter, just disable fuel pump. (remove relay)
May not even need the pressure tester, as the cooling system will be pressurized at operating temp in any event. But, using the tester, would give you a gauge, that would clue you in to any pressure bleed off. (which would indicate a leak somewhere.)
remove radiator cap. Run the engine up to operating temp. Remove spark plugs. See if you get coolant running out of any of the cylinders....... you should roll the motor over by hand, with a socket on the crank bolt or some such, and see if anything comes out... or, you could crank the engine with the starter, just disable fuel pump. (remove relay)
May not even need the pressure tester, as the cooling system will be pressurized at operating temp in any event. But, using the tester, would give you a gauge, that would clue you in to any pressure bleed off. (which would indicate a leak somewhere.)